<!DOCTYPE HTML>
<html reftest-async-scroll
      reftest-displayport-x="0" reftest-displayport-y="0"
      reftest-displayport-w="800" reftest-displayport-h="1000"
      reftest-async-scroll-x="0" reftest-async-scroll-y="50">
<body style="background:red; margin:0; overflow:hidden">
  <div style="position:absolute; background:lime; top:50px; left:0; width:800px; height:1000px"></div>
  <div style="position:absolute; background:yellow; bottom:-50px; left:50px; width:50px; height:50px"></div>
</body>
</html>
